1. Field of the Invention
The present invention relates to a disk drive, and more particularly, to a method of recording and/or reading system information of a single head disk drive.
2. Description of the Related Art
With regard to the operation of a disk drive, pieces of important information regarding recording and/or reading channels and a servo operation, i.e., system information, are stored in a different location than ordinary data. The reason is that damage to or loss of part of the system information may cause the entire disk drive to malfunction or stop functioning, while damage to or loss of the ordinary data does not considerably affect the operation of the disk drive. Therefore, the system information is stored in a much safer recording zone on a disk-type recording medium than a recording zone where the ordinary data is stored. Then, whenever the disk drive is turned on, the system information is read from the disk-type recording medium so that the disk drive is enabled to normally operate.
The system information on the operation of the disk drive includes servo correction/optimization information regarding a head's track following and seeking operations, channel optimization information regarding optimization of a reading channel, from which the head reads data, and a recording channel, in which the head records data, and defect information regarding physical defects on a disk-type recording medium. If the servo correction/optimization information is damaged or lost, track following and track seeking operations cannot be normally carried out, thus causing the disk drive to malfunction and increasing the time taken to search for desired data. If the channel optimization information is damaged or lost, data reading and data recording operations are carried out by simply using channel values that do not optimally reflect a data recording/reading environment for the hardware state of the disk drive. If the defect information is damaged or lost, important data may be accidentally recorded in a defective area from which data may not be properly read. In short, the system information is very important for proper operation of the disk drive.
A conventional disk drive records data on a plurality of recording media. Therefore, a plurality of heads are provided respectively for the plurality of recording media, and system information is stored in each of the plurality of recording media in order to guarantee the stability of the system information. Then, even when one of the plurality of recording media becomes defective due to external shock and thus the system information cannot be properly read from the defective recording medium, it is still possible to safely maintain the system information because the system information can be read from other recording media.
Currently, an increasing number of disk drives are manufactured with a single head rather than a plurality of heads. Due to the steady increase in the recording density of recording media, a single recording medium can achieve the same storage capacity that used to be provided by a plurality of recording media. In addition, using a single recording medium is more cost-effective than using a plurality of recording media. Moreover, by using a single recording medium, it is possible to manufacture a compact-sized disk drive. However, in the case of a disk drive with a single head, unlike in the case of a conventional disk drive adopting a plurality of recording media, it is impossible to make a backup of system information for guaranteeing the stability of the system information. Thus, once the system information is damaged or lost due to external shock, the entire disk drive may malfunction or undesirably stop functioning.
Therefore, the drive with a single head, like the disk drive with a plurality of heads, needs an efficient method of making a backup of system information necessary for the operation of the disk drive.